Scott Pruitt has been sworn in as the new head of the Environmental Protection Agency. Democrats pushed hard against Pruitt’s nomination and staged an all-night debate last night. They had called him unfit for the job. As Oklahoma’s attorney general, Pruitt sued the EPA more than a dozen times, and he promises to aggressively roll back what he calls the agency’s activist agenda. NPR’s Nathan Rott is with us now to talk about this. Hey, Nate.

NATHAN ROTT, BYLINE: Hey, Kelly.

MCEVERS: So what is Scott Pruitt likely to do?

ROTT: Well, it’s hard to say with any certainty. There have been hints of budget and staff cuts, but those have mostly come from people in the agency’s transition team so far who don’t speak for Mr. Pruitt himself. In his confirmation hearings, Pruitt did say that he wants to restore balance to the EPA, which can be read a few ways. He believes that the EPA and environmental regulation had been picking winners and losers in the last few years, especially under President Obama, the losers mostly being farmers, ranchers, oil and gas, industry basically. So I think it’s fair to say that he’s going to try to ease regulations for those groups.

I asked that question, though. What can he do to a lot of former EPA officials and administrators? Here’s the answer I got from Tracey Woodruff, a professor at the University of California, San Francisco, who worked at the EPA under Bill Clinton and George W. Bush.

TRACEY WOODRUFF: They could defund certain programs that they don’t like. They could try and identify things that they think are not useful, go after staff that they think are in – working in areas that they don’t agree with.

ROTT: And her list keeps going and going and going, so really there’s a lot of things.

MCEVERS: I mean, so will Pruitt be able to eliminate entire programs at the EPA? I mean, President Trump in the past has even talked about getting rid of the agency altogether.

ROTT: Yeah, he did. And he – I mean, he backed off of that claim later in the campaign, but that’s been a big concern for people. And I think really that’s the question we can answer with the most certainty. It’s very, very unlikely that the Trump administration can or would even want to get rid of the EPA. It’s just too complex of an agency. Here’s Christine Todd Whitman, administrator of the EPA under President George W. Bush.

CHRISTINE TODD WHITMAN: This is an agency that’s established by law. There are a number of pieces of legislation that have been passed to frame it. It’s not something that you can just wave a wand and do away with, nor do we want to.

ROTT: And really the same is true to an extent for a lot of the country’s bigger environmental regulations – the Clean Water Act, the Clean Air Act. One former administrator of the EPA put it to me this way. Deregulation takes just as much time as regulation. Which is a very D.C. way of saying it takes a really, really long time, possibly years, and there could be complications, like lawsuits.

MCEVERS: There already has been some tension at the EPA since Trump’s inauguration. You reported on a clamp down on communications and concerns about how scientists’ work would be vetted. How will Pruitt be received by the agency?

ROTT: I think that’s going to be one of the most interesting things to watch in the coming days and weeks. I mean, you’ve got nearly 800 former EPA employees who signed a letter saying that Pruitt is unfit for the office. You’ve got current employees leaking memos and participating in rallies against him. Christine Todd Whitman, that former administrator we heard from earlier, said that this is unprecedented. She’s never seen this level of animosity between existing staff and an incoming EPA head.

And we could see that flare in the next week. An Oklahoma judge yesterday ruled that Pruitt has to turn over thousands of emails and other documents between himself and fossil fuel companies by next Tuesday. And so if that shows a disregard for science or closer ties to industry, it could get a really big backlash.